It'll take some work with Vil getting used to How He Is, but so long as the changes WERE actually good and well thought out, he would at least be willing to work with him on it- but only during practice. Once it's show time he'd demand that no more changes be made- with the exceptions of props breaking/people forgetting lines/other accidents. Then he'll have free reign to "fix" it. That'd probably have to be the compromise.

Break the rule and he gets a pay cut.